He added that the specials will feature just the show's regular cast of Matt Smith, Karen Gillan and Arthur Darvill.

"There isn't a guest character, it's just the three of them," he explained. "A moment of life aboard the Tardis. But obviously life about the Tardis instantly gets you into terrible jeopardy, and all of causality is threatened."

Comic Relief: Funny For Money on Red Nose Day begins on March 18 at 7pm on BBC One.